Sulfur vat dye and process of making same.



UNITED STATES PATENT OFFICE.

BERTRAM MAYER AND ADOLF PFANNENSTIEL, OF BASEL, SWITZERLAND, ASSIGNORSTO SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASEL,'SWITZERLAND.

SULFUR VAT DYE AND PROCESS OF MAKING- SAME.

Specification of Ihetters Patent.

Patented July 13, 1909.

Application filed September 24, 1908. Serial No. 454,629.

To all who'nt it may concern:

Be it known that We, BERTRAM MAYER,

doctor of philoso by and chemist, and Aoow PFANNENSTIEL, (octor ofhilosophy and chemist, both subjects of tlic King of Bavaria, andresidents of Basel, Switzerland, have invented new and useful SulfuretedVat Dyestuffs and a Process of Making Same, ofwhich the following is afull, clear, and exact specification.

We have found, that by-heating Q-methyl- .-ben zanthrone with sulfur oralkali polysulfids to "a high temperature, new sulfureted dyestuffs areproduced, which dye unmordanted cotton from an alkaline hydrosulfite vatbluish green, olive, greenish black to deep' black shades of excellentfastness to washing, light and chlorin. I

' The following examples illustrate the invention:

Example 1: 10 parts of 2-methylbenzanthrone are. heated with parts ofsulfur to 200-240 C. until the evolution of hydro-'- gen sulfid hasceased. The cooled massis finely powdered and the excess of sulfur isextracted from it by carbon-bisulfid or a sodium sulfid solution. Thedyestufi thus purified is a nearly black powder, insoluble in mostorganic solvents. It dissolves, ditiicultly in boiling nitrobenzene witha dirty Bordeaux-red color and intensive fluorescence, Its solution inconcentrated sulfuric acid shows a violet-red, and in fuming sulfuricacid a violet-black coloration. With hydrosullite the dyestuff yields anolive colored vat'from which cotton is dyed in green shades turning to avery fast blue-greenby exposure to the air.

Example '2: 10 parts of Q-methylbenzanthrone are heated with 40-50 partsof sulfur to 300330 C. until the evolution of hydrogenysulfid hasceased. The resultin dye- 'stufi dissolves in concentrated sulfuric acidwith aydirty violet-red coloration and in filming sulfuric acid with abrown-black- .eolor. In boiling nitrobenzene it is only ditiioultlysoluble with a brown-red color and intensive fluorescence. The alkalinehydrosulfite vat is olive. On cotton the new dyestuff yields deep blackdyeings of excellent fastness to washingand chlorin.

Example 3: 10 parts of Q-methylbenzanthrone are heated with 100 parts ofsodium tetrasulfid during one hour to 200240 C. The cooled melted massis dissolved in hot water and filtered. The residue is washed with waterand dried. .It forms a black;

powder and may be used directly for dyeing. The new dyest-uflr'dissolves in concentrated sulfuric acid withbrown-red and in fumingsulfuric acid with a brown coloration. In

hot nitrobenzene it is scarcely soluble. With 4 caustic soda lye andhydrosulfite it yields a blue vat, from which cottonis dyed in blueshades turning from blackish'olive to greenv black by their expositionto theair.

The hereinbefore mentioned proportions of methylbenzanthrone and sulfuror alkali;

polysulfid and also the temperature maybe varied withinwide limits.

What we claim is: 1. The described process for the manufacture ofnew-sulfureted vat-dyestuffs of the anthracene-series, which consists inheatingQ-methylbenzanthrone with sulfur to ,a high temperature.

2. The described process for the manu-.

facture of newsulfureted vat-dyestuffs of the anthracene-series, whichconsists in heat: ing Q-methylbenzanthrone with an alkali polysulfid toa high temperature.

'3. As new products, the vat-dyestuffs ob Iri witness whereof, We havehereunto siined our names'in the presence of two 10 su scribingWitnesses.

BERTRAM MAYER. ADOLF PFANNENSTIEL.

Witnesses:

ERNST WAGNER, AMAND BITTER.

